目的:全面回顾了不同运动方式在老年肌少症防治中的干预效果,重点关注抗阻运动的剂量效应,旨在为肌少症防治的运动干预临床实践提供精准化策略。方法:通过检索PubMed、Web of Science、中国知网等数据库,筛选近期相关随机对照试验(RCT)...目的:全面回顾了不同运动方式在老年肌少症防治中的干预效果,重点关注抗阻运动的剂量效应,旨在为肌少症防治的运动干预临床实践提供精准化策略。方法:通过检索PubMed、Web of Science、中国知网等数据库,筛选近期相关随机对照试验(RCT)、系统综述和Meta分析,针对不同运动方式对肌少症的防治效果及抗阻运动剂量效应进行分析。结论:不同运动方式在肌少症防治中表现出差异化特征与互补效应,抗阻运动在提升肌肉质量和力量方面疗效显著;有氧运动通过改善代谢与心肺功能,延缓肌少症进展;多组分运动通过整合多重效应,全面优化身体功能;全身振动训练(WBVT)与血流限制训练(BFRT)可为体力受限人群提供安全、可行的替代方案。抗阻运动是老年肌少症运动干预的核心手段,60%~80%1RM、每周2~3次、多组数高量抗阻运动方案在提升肌肉质量和力量上效果最优;30%~40%1RM单组数低量抗阻运动方案亦可获益,适合虚弱或初练者。应依据个体基线、恢复能力,在兼顾有效性、安全性和依从性的基础上,构建精准化、可长期执行的抗阻运动方案,并联合其他运动模式,实现老年肌少症最佳干预效果。展开更多
The multidimensional modal theory proposed by Faltinsen, et al. （2000） is applied to solve liquid nonlinear free sloshing in right circular cylindrical tank for the first time. After selecting the leading modes and ...The multidimensional modal theory proposed by Faltinsen, et al. （2000） is applied to solve liquid nonlinear free sloshing in right circular cylindrical tank for the first time. After selecting the leading modes and fixing the order of magnitudes based on the Narimanov-Moiseev third order asymptotic hypothesis, the general infinite dimensional modal system is reduced to a five dimensional asymptotic modal system （the system of second order nonlinear ordinary differential equations coupling the generalized time dependent coordinates of free surface wave elevation）. The numerical integrations of this modal system discover most important nonlinear phenomena, which agree well with both pervious analytic theories and experimental observations. The results indicate that the multidimensional modal method is a very good tool for solving liquid nonlinear sloshing dynamics and will be developed to investigate more complex sloshing problem in our following work.展开更多
In fault diagnosis of rotating machinery, Hil- bert-Huang transform （HHT） is often used to extract the fault characteristic signal and analyze decomposition results in time-frequency domain. However, end effect occu...In fault diagnosis of rotating machinery, Hil- bert-Huang transform （HHT） is often used to extract the fault characteristic signal and analyze decomposition results in time-frequency domain. However, end effect occurs in HHT, which leads to a series of problems such as modal aliasing and false IMF （Intrinsic Mode Func- tion）. To counter such problems in HHT, a new method is put forward to process signal by combining the general- ized regression neural network （GRNN） with the bound- ary local characteristic-scale continuation （BLCC）. Firstly, the improved EMD （Empirical Mode Decompo- sition） method is used to inhibit the end effect problem that appeared in conventional EMD. Secondly, the gen- erated IMF components are used in HHT. Simulation and measurement experiment for the cases of time domain, frequency domain and related parameters of Hilbert- Huang spectrum show that the method described here can restrain the end effect compared with the results obtained through mirror continuation, as the absolute percentage of the maximum mean of the beginning end point offset and the terminal point offset are reduced from 30.113% and 27.603% to 0.510% and 6.039% respectively, thus reducing the modal aliasing, and eliminating the false IMF components of HHT. The proposed method caneffectively inhibit end effect, reduce modal aliasing and false IMF components, and show the real structure of signal components accuratelX.展开更多
文摘目的:全面回顾了不同运动方式在老年肌少症防治中的干预效果,重点关注抗阻运动的剂量效应,旨在为肌少症防治的运动干预临床实践提供精准化策略。方法:通过检索PubMed、Web of Science、中国知网等数据库,筛选近期相关随机对照试验(RCT)、系统综述和Meta分析,针对不同运动方式对肌少症的防治效果及抗阻运动剂量效应进行分析。结论:不同运动方式在肌少症防治中表现出差异化特征与互补效应,抗阻运动在提升肌肉质量和力量方面疗效显著;有氧运动通过改善代谢与心肺功能,延缓肌少症进展;多组分运动通过整合多重效应,全面优化身体功能;全身振动训练(WBVT)与血流限制训练(BFRT)可为体力受限人群提供安全、可行的替代方案。抗阻运动是老年肌少症运动干预的核心手段,60%~80%1RM、每周2~3次、多组数高量抗阻运动方案在提升肌肉质量和力量上效果最优;30%~40%1RM单组数低量抗阻运动方案亦可获益,适合虚弱或初练者。应依据个体基线、恢复能力,在兼顾有效性、安全性和依从性的基础上,构建精准化、可长期执行的抗阻运动方案,并联合其他运动模式,实现老年肌少症最佳干预效果。
基金Project supported by the National Defense Pre-research Foundation of‘Tenth Five-Year-Plan’of China (No.41320020301)
文摘The multidimensional modal theory proposed by Faltinsen, et al. （2000） is applied to solve liquid nonlinear free sloshing in right circular cylindrical tank for the first time. After selecting the leading modes and fixing the order of magnitudes based on the Narimanov-Moiseev third order asymptotic hypothesis, the general infinite dimensional modal system is reduced to a five dimensional asymptotic modal system （the system of second order nonlinear ordinary differential equations coupling the generalized time dependent coordinates of free surface wave elevation）. The numerical integrations of this modal system discover most important nonlinear phenomena, which agree well with both pervious analytic theories and experimental observations. The results indicate that the multidimensional modal method is a very good tool for solving liquid nonlinear sloshing dynamics and will be developed to investigate more complex sloshing problem in our following work.
基金Supported by National Natural Science Foundation of China(Grant No.51375467)Quality Inspection of Public Welfare Industry Research Projects,China(Grant No.201410009)
文摘In fault diagnosis of rotating machinery, Hil- bert-Huang transform （HHT） is often used to extract the fault characteristic signal and analyze decomposition results in time-frequency domain. However, end effect occurs in HHT, which leads to a series of problems such as modal aliasing and false IMF （Intrinsic Mode Func- tion）. To counter such problems in HHT, a new method is put forward to process signal by combining the general- ized regression neural network （GRNN） with the bound- ary local characteristic-scale continuation （BLCC）. Firstly, the improved EMD （Empirical Mode Decompo- sition） method is used to inhibit the end effect problem that appeared in conventional EMD. Secondly, the gen- erated IMF components are used in HHT. Simulation and measurement experiment for the cases of time domain, frequency domain and related parameters of Hilbert- Huang spectrum show that the method described here can restrain the end effect compared with the results obtained through mirror continuation, as the absolute percentage of the maximum mean of the beginning end point offset and the terminal point offset are reduced from 30.113% and 27.603% to 0.510% and 6.039% respectively, thus reducing the modal aliasing, and eliminating the false IMF components of HHT. The proposed method caneffectively inhibit end effect, reduce modal aliasing and false IMF components, and show the real structure of signal components accuratelX.
